Apparently, the lone alleged bomber was sitting in a wheelchair holding some sort of IED in one hand and trigger device in another, setting off black powder (from firecrackers) resulting in loud bang & smoke - and was injuried/being attended to by police & medical people. No others hurt in this incident ...

http://news.sina.com.hk/news/2013072...3021814/1.html

http://www.usatoday.com/story/news/w...osive/2570855/

Details are sketchy and often imprecise in early/initial raw reporting in the confusion. Expect tighter security until the facts are sorted out.